1. Field of the Invention
The present invention relates to automatic devices and methods intended for chemical analyses. In particular, the invention relates to the analysis in automatic analysers of solutions formed by samples and reagent substances.
2. Description of Background Art
Samples have traditionally been examined using analysers, which have changed from manually operated test devices to automated multi-purpose devices. Present analysers can perform several different tests and can be used to achieve comparatively short throughput times, as well as good productivity with low personnel costs. In conventional automatic analysers, a circular rotatable incubator is traditionally used, on the outer circumference of which openings are made to receive cuvettes. The cuvettes placed in the incubators are usually reaction vessels, into which the analyser doses the substance to be analysed and the reagent substances causing reactions.
A move has taken place from the individual reaction vessels of traditional incubators to cuvettes, which contain several reaction vessels, which has increased the efficiency of analysers. For example, publication U.S. Pat. No. 5,104,808 A discloses an automatic incubator having curvaceous openings, to at least one of which has a cluster for reaction vessels, from which cluster the sample can be analysed optically after it has been mixed with reagent substances. Reaction vessels having elastic bindings, on the other hand, are known from publication U.S. Pat. No. 5,720,406 A, which discloses a principle of bending reaction vessels to curvaceous openings without analysing the samples while in a reaction vessel. Furthermore, publication EP 0577822 B1 discloses a method of cutting a portion, having at least two cuvettes, of an elastic cuvette belt and transporting the portion to openings on the perimeter of a rotatable carousel. Publication U.S. Pat. No. 5,096,672 A also discloses a cuvette row having a plurality of cuvettes, which cuvette row can be shaped in a curved form.
A problem with the type of device described has been the low degree of modularity of the analysers and the cuvettes they use. In analysers designed for present systems for large numbers of analyses, there are large incubators, into which a significant number of cuvette assemblies can be loaded. However, these cuvette assemblies cannot be utilized in analysers intended for smaller numbers of samples, so that a special type of cuvette assembly is required for each size of device, which leads to additional purchase and storage costs.